曼型干式煤气柜动力特性分析及风振响应主要贡献模态识别

Dynamic characteristics of a MAN type dry gas storage tank and recognition of main modes with contributions to its wind-induced vibration

曼型干式煤气柜不同于一般空间结构,其动力特性十分复杂,作为研究其频域内风振响应的基础,首先通过建立精细化有限元模型研究其在不同工况下的动力特性;其次,分别计算背景、共振响应振型能量参与系数,并按降序排列,选取结构风振响应的主要模态;最后,通过选取模态进行频域计算并与传统频域计算方法(完全二次振型叠加,CQC法)对比。结果表明:结构自振频率分布密集;动力特性受活塞位置及内部气压影响较大;背景、共振响应振型能量参与系数能准确反映各阶模态能量对响应总能量的贡献程度;通过振型能量参与系数法确定的主要模态进行频域分析具有计算效率高,计算精度可控的优点。

The dynamic characteristics of a MAN type dry gas storage tank are very complex,they are different from those of ordinary spatial structures. Here,as the basis of its wind-induced response analysis in frequency domain,its dynamic characteristics were analyzed under different working conditions by using the finite element method. Its modes were sorted with order-descending according to the calculation results of mode energy participation factors of background response and resonant response,respectively. Then,the modes with significant contributions to its wind-induced vibration were selected. Finally,the results calculated in frequency domain with a selected modes were compared with those calculated with CQC method. The results showed that the modal frequency distribution of the structure is dense; the location of piston and internal pressure have larger influences on the dynamic characteristics of the gas storage tank; the mode energy participation factors of background response and resonant one can reflect the contributions of different order modes＇ energy to the total energy of the response; the analysis in frequency domain with the main modes determined using the mode energy participation factors has advantages of higher calculation efficiency and controllable computation accuracy.